Mitsubishi Galant (2004+). Manual - part 1601

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-297

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC B1499 set?

YES : Replace the SRS-ECU (Refer to 

P.52B-365

).

NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-6

).

DTC B1519: Connector Lock System Detects Connector Unlocked

CAUTION

If DTC B1519 is set in the SRS-ECU, always diag-
nose the CAN main bus line.

.

DTC SET CONDITIONS
This DTC is set if a poor connection at the SRS-ECU 
is detected. However, if the vehicle condition returns 
to normal, DTC number B1519 will be automatically 
erased, and the SRS warning light will go out.

.

TROUBLESHOOTING HINTS

• Damaged connectors

• Malfunction of the SRS-ECU

.

DIAGNOSIS

Required Special Tool:

•  MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A (Vehicles with CAN 

communication system)

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-298

STEP 1. Using scan tool MB991958, diagnose the CAN bus 
line.

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958. Refer to "How to connect the 

scan tool 

P.52B-30

.."

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO :  Repair the CAN bus line (Refer to GROUP 54C, 

Diagnosis 

P.54C-14

).

STEP 2. Recheck for diagnostic trouble code.

Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.

(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Go to Step 3. 
NO :  There is an intermittent malfunction such as poor 

engaged connector(s) or open circuit (Refer to 
GROUP 00, How to Cope with Intermittent 
Malfunction 

P.00-6

).

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-299

STEP 3. Check the SRS-ECU connector C-120, C-121 and 
C-122.

Q: Are connectors correctly engaged?

YES : Go to Step 4.
NO :  Engage the connectors correctly. Then go to Step 5.

AC307741

CONNECTORS: C-120, C-121, C-122

C-120 (Y),
C-121 (Y),
C-122 (Y)

AB

SRS-ECU

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

C-120 Harness side
connector (rear view)

C-121 Harness side
connector (rear view)

42

31

38

27

21

41

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

C-122 Harness side
connector (rear view)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

SRS AIR BAG DIAGNOSIS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-300

STEP 4. Check SRS-ECU connector C-120, C-121 and 
C-122 for damage.

(1) Disconnect SRS-ECU connectors C-120, C-121 and C-122.
(2) Check the connector lock switch terminal inside the harness 

side connector for improper contact or deformation.

Q: Are the SRS-ECU connector C-120, C-121 and C-122 in 

good condition? 
YES : Erase the diagnostic trouble code memory, and check 

the diagnostic trouble code. If DTC B1519 sets, 
replace the SRS-ECU. (Refer to 

P.52B-365

). Then go 

to Step 5.

NO :  Replace the SRS-ECU connector C-120, C-121 and 

C-122. Refer to GROUP 00E, Harness Connector 
Inspection 

P.00E-2

. Then go to Step 5.

AC307741

CONNECTORS: C-120, C-121, C-122

C-120 (Y),
C-121 (Y),
C-122 (Y)

AB

SRS-ECU

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

C-120 Harness side
connector (rear view)

C-121 Harness side
connector (rear view)

42

31

38

27

21

41

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

C-122 Harness side
connector (rear view)

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

AC307924 AB

SRS-ECU HARNESS SIDE 
CONNECTOR (FRONT VIEW)

CONNECTOR LOCK
SWITCH TERMINAL